In commercial aircraft, safety requirements dictate that the passenger be provided with air containing sufficient oxygen given a pressure drop in the cabin.
Oxygen or oxygen-enriched air can be generated using chemical oxygen generating systems or gaseous oxygen systems, for example. When using chemical oxygen generating system, use is made of oxygen generating systems with sodium chlorate candles, for example, enabling the chemical generation of oxygen by burning down these sodium chlorate candles. Once the reaction has been started, it can most often not be terminated or interrupted, and the sodium chlorate candle burning time is limited to approximately 15 to 22 minutes. When using chemical gas reactors, the used chemicals (e.g., sodium chlorate candles), are be replaced after use or after approximately 15 years at the latest. In addition, chemical reactions are accompanied by high temperatures of approximately 260° C., making integration into cabin elements (e.g., into a passenger seating element) critical.
When using gaseous oxygen systems (e.g., an oxygen storage tank is arranged in an aircraft), the required oxygen is supplied to the passenger via intricate tubing systems subject to special protective measures. This necessitates a high installation outlay, along with complex tightness tests of the tubing system. This is necessary in particular since gaseous oxygen greatly facilitates the spread of fire, and is classified as a hazardous substance, so that strict rules in handling oxygen must be followed. Another side effect is that the used system elements (e.g., the oxygen reservoir or valve settings) must constantly be monitored. This oxygen reservoir must additionally always be carried along and maintained. In addition, the inflexible tubing system can make reconfiguring cabin elements complicated (e.g., shifting seating elements, since the oxygen distribution system must be adjusted). This results in difficulties in the providing oxygen in a cabin element (e.g., a seating element), since the pneumatic connection to the primary oxygen distribution system must be continuously adjusted.
Oxygen systems used in cabin elements (e.g., in a seating element), have to date been based on chemical oxygen generation. DE 4227377 shows a seat design for an airline passenger seat with a chemical oxygen generating system, and a container for generating oxygen is arranged in the seat floor under the seat floor cushion. The container generates oxygen via chemical reaction, and relays it to the oxygen masks via oxygen-carrying tubing. DE 195 34 025 describes supply units arranged in a laterally allocated column of a passenger seat.
In addition, an oxygen supply unit can be used to enrich breathable air with oxygen, which the cabin air uses for generating oxygen-enriched air. A molecular sieve that operates based on the so-called pressure-swing-absorption principle (PSA) can here be used, for example. EP 1 598 103 and AU 4366396 describe portable oxygen concentration systems, which generate oxygen according to the pressure-swing-absorption principle. DE 2901938 describes a flowing agent separating with a molecular sieve, with which an oxygen-enriched product can be generated from pressurized air. EP 135 89 11 describes a system for generating oxygen based on a molecular sieve principle on board an aircraft.
In view of the foregoing, it may be seen as a need to enable a flexible, modular cabin unit with an oxygen supply. In addition, other needs, desirable features, and characteristics will become apparent from the subsequent summary, detailed description, and the appended claims, taken in conjunction with the accompanying drawings and this background.